The United States offers a diverse public transportation network, primarily in urban areas, encompassing various forms of bus, rail, ferry, and even some airline services. Amtrak, the national intercity rail system, spans the contiguous U.S., notably featuring the Acela Express—the only operating high-speed rail in the Americas—within its Northeast Corridor. While most services are publicly funded, Florida's Brightline stands out as a unique for-profit private intercity passenger rail service. Historically, public transit declined significantly after the 20th century's rise of automobiles. Consequently, the U.S. lags behind other developed nations in public transport usage, with a 2012 study showing just 24 annual trips per capita, largely attributed to factors like low-density cities and high car ownership.